Change local web server back to WEBrick in Rails from Puma

To run the local server in development with webrick you should only have to specify it when running rails server:

rails server webrick

You may get it to default back to webrick again if you move puma to the production group of your Gemfile:

group :production do
  gem 'puma'
end

Then bundle without the production group:

bundle install --without production

Per the following:

How to set Rails dev server to webbrick instead of Puma

You want to change your Gemfile to:

group :production do
  gem 'puma'
end

And running bundle install --without production will set WEBrick as the non-production (development & test) server and Puma to production.

Remove the puma gem from the gemfile and bundle it.

and start the application. you can see the webrick app server start info in the console.

Default app web server is Webrick